This invention relates to a new process for preparing polyolefins.
Heretofore, various methods have been known for preparing polyolefins, for example, a method wherein there is used a catalyst consisting of an inorganic magnesium solid such as magnesium halide, magnesium oxide or magnesium hydroxide and a transition metal compound such as a vanadium compound supported thereon. In these known techniques, however, the particles of the resulting polymer are amorphous, the bulk density is generally low and the particle size distribution is generally wide, so that a large amount of product is finely powdered, for which reason improvements have been sought from the standpoint of productivity and slurry handling. In addition, molding of polymers prepared according to such conventional methods causes dust problems and lowered molding efficiency. There have therefore been strong efforts to increase bulk density and reduce the amount of finely powdered material.
It is an object of this invention to remedy the above-mentioned drawbacks.
It is another object of this invention to provide a process for preparing polyolefins having a high bulk density, a narrow particle size distribution and a reduced proportion of finely powdered material.
It is a further object of this invention to provide a process for preparing polyolefins having the aforesaid characteristics as well as well shaped of polymer particles.
Other objects and advantages of this invention will become apparent from the following description.